Astronomers propose lower-cost and more powerful James Webb alternative

They suggest that diffractive lenses could be the key to peering at distant alien worlds with never-before-seen clarity.
Chris Young
An artist's impression of the Nautilus Space Observatory.
An artist's impression of the Nautilus Space Observatory.

Katie Yung, Daniel Apai /University of Arizona and AllThingsSpace /SketchFab, CC BY-ND 

An astronomer who studies astrobiology has detailed the work their team has carried out developing a new kind of telescope that could far exceed the James Webb Space Telescope's ability to peer at distant alien worlds.

In a report for The Conversation, Daniel Apai, professor of astronomy and planetary sciences at the University of Arizona, explains that a new breakthrough in diffractive lens technology could drastically cut the cost of developing powerful lenses.

These could be used in a network configuration to outperform the world's most powerful space observatory, James Webb.

Meet the Nautilus Space Observatory

NASA has so far discovered roughly 5,000 planets outside our solar system. These planets, referred to as exoplanets, could help us learn a great deal about the evolution of the cosmos, and they may even lead to the discovery of alien life.

More powerful observatories are needed, though, to analyze these planets in greater detail, Apai points out.

He has been co-leading a team developing the Nautilus Space Observatory, which would break the mold of conventional telescopes. Unlike Hubble and James Webb, Nautilus will not collect light using mirrors. Instead, it will replace those large heavy mirrors with a new type of thin lens that is lighter, cheaper, and easier to produce.

Due to the lower cost compared with conventional telescopes, it would be possible to launch several individual units to orbit and create a large network. According to Apai, this would exceed the observational capabilities of the $10 billion James Webb telescope, allowing astronomers to peer at exoplanets like never before.

Webb is the most powerful space observatory to date, and it has allowed scientists to characterize the atmospheric composition of several exoplanets.

Using the new thin lens method, Apai and his team believe they can go even further and begin studying the chemical composition of these planets' surfaces. The key to this is an old technology called diffractive lenses.

New diffractive lenses could disrupt astronomy

The team behind Nautilus came up with their idea when they were asked by Northrop Grumman in 2016 to come up with a vision of telescopes 50 years from now, alongside 14 other professors and NASA scientists.

They concluded that one of the major bottlenecks preventing the construction of more powerful telescopes is the difficulty in constructing the massive mirrors required for conventional observatories.

Conventional lenses use refraction to focus light, meaning they change the direction of light when it passes from one medium to another — like when light enters water. Diffraction, meanwhile, is when light bends around corners and obstacles. This can be achieved by arranging a pattern of steps and angles on a glass lens.

Today, these types of lenses are typically used in small consumer optics, such as camera lenses and virtual reality headsets. Diffractive lenses are known for producing blurry images, which is why they haven't traditionally been used for astronomical observations.

Apai and his team have worked on producing a new type of diffractive lens that produces a much higher-quality image. What's more, because it's the surface texture of the lens rather than its thickness doing the focusing, it's easy to make the lens larger while keeping it thin and lightweight.

With NASA not expecting to launch a successor to James Webb until the 2040s — the multi-billion-dollar Habitable World Observatory (HWO) will be tasked with investigating exoplanets — the Nautilus team could present diffractive lenses as an ideal alternative that could help us peer further into the distant cosmos at a fraction of the cost.

Add Interesting Engineering to your Google News feed.
Add Interesting Engineering to your Google News feed.
message circleSHOW COMMENT (1)chevron
Job Board